in Terms of the Mechanical Equivalent of Heat. 11 



tion of J were obtained by measuring a large number of 

 equidistant ordinates, calculating the area of the curve, and 

 dividing by the base-line. If a, b, c, and d are the mean 

 readings thus obtained, 2# = a — b and 20 / = c—d as the galva- 

 nometer was graduated from 0° to 360°. Thus the zero- 

 point was not used, though observed before and after each 

 experiment. 



Below are the results of one experiment in detail. Each 

 value of J is calculated from the two temperatures found in 

 the same horizontal line. 



Series of December 9th. 



Weight of calorimeter and water before experiment . 1157*2 

 Weight of calorimeter and water after experiment . 1157*0 



1157-1 

 Weight of calorimeter . . 343*7 



813*4 

 Capacity of calorimeter 30 '4 



843-8 

 Capacity reduced to weight in vacuo 844*8 



Horizontal magnetic force before experiment . . . 'I960 

 Horizontal magnetic force after experiment . . . '1963 



Mean -19615 



o o 



Temperature of jacket .... 21*5 to 21'6 



Temperature of air near stem . 22 '8 to 23*4 



Temperature of 30,000-ohm coil. 21'5 to 22*3 



Thermometer in calorimeter . . Baudin 7320 



Time. 



Beading 

 7320. 



Stem. 



2A. 



Time. 



Eeading 

 7320. 



Stem. 



2A. 



m. s. 









m. s. 









8 40 



19-45 



-•010 







25 14 



25-40 



+ -009 



+ •056 



13 16 



2115 



-•007 



-•018 



31 9 



27*40 



•021 



•167 



20 38 



23-80 



•000 



+•005 



35 58 



28-98 



•029 



•299 



25 14 



25-40 



+ •009 



•056 



42 54 



31-15 



•039 



•565 



- 







20. , 



20'. 



J. 









o / 



51 84 



7 35-6 



41810000 









50 57*5 



7 28-5 



41640000 















50 48-5 



7 24-4 



41640000 















50 404 



7 21-4 , 



41840000 









